ω-3 PUFAs Attenuate Postoperative Ileus by Modulating the NLRP3/Caspase-1/IL-1β Inflammatory Axis

Abstract Postoperative ileus (POI) is partly driven by intestinal inflammation and macrophage activation. We investigated whether omega-3 polyunsaturated fatty acids (ω-3 PUFAs) alleviate POI by modulating macrophage polarization and NLRP3 inflammasome signaling. C57BL/6 mice with intestinal manipulation-induced POI received different doses of ω-3 PUFAs. Ileal injury, intestinal transit, inflammatory mediators, macrophage phenotypes, and inflammasome-related proteins were assessed, and data-independent acquisition proteomics was used to identify candidate pathways. In vitro, PMA-differentiated THP-1 macrophages were stimulated with lipopolysaccharide and ATP, with MCC950 used as an NLRP3 inhibitor control. ω-3 PUFAs reduced ileal injury, preserved villus architecture, improved intestinal transit and smooth muscle-related markers, and decreased IL-1β and IL-18 levels in POI mice. Proteomics highlighted the NOD-like receptor signaling pathway. ω-3 PUFAs also reduced macrophage infiltration and M1-like polarization, promoted M2-like polarization, and suppressed NLRP3 inflammasome activation, Caspase-1 activation, and GSDMD-mediated pyroptosis in vivo and in vitro. These findings indicate that ω-3 PUFAs alleviate POI-associated intestinal inflammation and dysmotility by modulating macrophage polarization and suppressing NLRP3/Caspase-1/IL-1β signaling, supporting their potential as a nutritional intervention for POI.